Apparatus for hydraulically removing and replacing interference fitted parts and the like



3, 1966 H. M. JOHNSON ETAL 3, 6 ,568

APPARATUS FOR HYDRAULICALLY REMOVING AND REPLACING INTERFERENCE FITTEDPARTS AND THE LIKE Filed May 8, 1963 4 Sheets-Sheet 1 INVENTORSI HOWARDM. JOHNSON JEFFERY D. IRONS ATTORNEYS g- 23, 1956 H. M. JOHNSON ETAL3,267,568

R H LY REMOVI APPAR S ICAL NG AND PLACING TE RE TTED PARTS AND THE EFiled May 8, 1963 4 Sheets-Sheet 2 1N NTORS:

HOWARD JOHNSON JEFFERY D [R0 NS ATTORN EYS g- 1966 H M. JOHNSON ETAL 37, 68

APPARATUS FOR HYDRAULICALLY REMOVING AND REPLACING INTERFERENCE FITTEDPARTS AND THE LIKE Filed May 8, 1963 4 Sheets-Sheet 5 2 220 226 222 228214 as f INVENTORSI HOWARD M. JOHNSON JEFFERY D. IRONS BY M4Mm-ATTORNEYS Aug. 23, 1966 H M. JOHNSON ETAL 8 APPARATUS FOR HYDRAULICALLYREMOVING AND REPLACING INTERFERENCE FITTED PARTS AND THE LIKE INVENTORS:HOWARD M. JOHNSON JEFFERY D. IRONS BY IM ATTORNEYS 3,267,568 APPARATUSFGR HYDRAULIiJALLY REMQVWG AND REPLACING INTERFERENCE FITTED PARTS ANDTHE LIKE Howard M. Johnson, Lafayette, La, and Jeffery D. Irons, Tulsa,Okla, assignors to Orbit Valve (Iompany, Tuisa, 0kla., a corporation ofOklahoma Filed May 8, 1963, Ser. No. 278358 8 Claims. (Cl. 229-413) Thisinvention relates to apparatus for separating interference fitted parts.More specifically, the invention relates to apparatus for hydraulicallyseparating valve seats from valve bodies which have been fitted with ahigh degree of interference.

It is a Well known engineering design function to fit parts togetherwith a high degree of interference such that in normal usage the partswill not move relative to one another. Typically such interference fitoccurs by dimensionally designing the parts such that their fit comesabout by a press or a shrink process. Parts that have been joined inthis manner frequently represent the best possible design permissive ofequalizing stresses from one part to the other. In many valves and pumps21 high interference fit between a seat ring and the body performs thesealing function in a manner not possible by any other means exceptintegrally welding or soldering the mating pieces together. It has alsobeen known that a high degree of press fit produces a high contactpressure between the mating parts and in addition to the scalingfunction all fluid is excluded from between the parts. This has beenknown to prevent corrosion from occurring even when the mating parts aredissimilar metals.

Additionally, it has been known to be advantageous in the constructionof certain rotating machinery as centrifugal and axial flow pumps andcompressors to press fit the impellers on the shaft. Such a designimparts intrinsic, static and dynamic balance to the rotating assembly.One of the problems, however, has been the difiiculty in disassembly ofthe mating parts.

It is also Well known in the engineering arts that high interferencefitted parts can usually be joined together with comparative ease, butsuch interference fitted parts are frequently omitted from engineeringdesign because of the problems in separating the parts later. Typical ofthis problem is in the construction of valve seats in valve bodies.Typically, the seat is installed at the manufacturers plant usinghydraulic presses and other available equipment. Ordinarily with suchequipment the seat can be removed from the valve. The problem remains,however, in the removal of the seat at its inline looation after it hasonce left the factory. It has been found that in many instances inremoving valve seats from valve bodies using mechanical pullers or meansan uneven pulling force is applied to bind to the walve seat within itsbore. Typically this results in injury to the bore necessitating agrinding operation and replacement with an oversized valve seat. In manyinstances such procedures are difiicult if not impossible at the fieldlocation of the valve.

Accordingly, it is a primary object of this invention to provideapparatus for overcoming the problems heretofore associated withinterference fitted parts.

It is another object of this invention to provide an apparatus forseparating interference fitted parts, hydraulically, and with equipmentreadily available and usable at the location of the equipment or partsand without removal of the equipment or interfering with its futureoperation.

It is a particular object of this invention to provide apparatus forhydraulically separating v alve seats from valve bodies using hydraulicequipment, which is readily availnited States Patent able and usable atthe on-line location of the valve, and without removing the valve fromits position.

A still further object of this invention is to provide apparatus whichcan be used internally of cylindrical mating parts for separatinginterference fitted parts by external application of hydraulic pressure.

A yet further object of this invention is to provide an apparatuscapable of hydraulically separating interference fitted parts whereinthere is equality and inequality of diameters with respect to theinterference fitted parts.

Still another object of this invention is to provide an apparatus forhydraulically replacing parts in interference fitted relation.

These and other objects of this invention will become more apparent uponfurther reading of the specifications and claims when taken inconjunction with the following illustrations of which:

FIGURE 1 is a sectional view, partly in elevation, of the preferredapparatus for removing interference fitted valve seats from valve bodieshydraulically.

FIGURE 2 is a sectional view, partly in elevation, describing apparatusfor hydraulically removing valve seats from valve bodies in thoseinstances where the internal bores are of unequal diameter.

FIGURE 3 is a partial sectional view of an apparatus constructed inaccordance withthis invention for removing a die bushing from a die set.

FIGURE 4 is a partial sectional view of an apparatus for hydraulicallyremoving cylindrical interference fitted parts which have the sameexterior diameter.

FIGURES 5 and 6 are partial sectional views of an apparatus for removingcylindrical interference fitted parts which are of unequal outsidediameter.

FIGURES 7, 8, 9, 10, 11 and 12 represent additional modifications ofthis invention.

FIGURE 13 represents an additional embodiment of this invention forinserting valve seats within a valve body.

General description Broadly speaking, this invention is concerned withseparating interference fitted parts by hydraulic pressure. The variousapparatus herein create a confined (annular space across theinterference fitted parts. A force equal to the product of the hydraulicpressure and the annular crosssectional area of the object which is tobe displaced is applied to cause separation. In essence, the cylindricalbody which is to be removed becomes an annular piston to overcome thefriction of its interference fit with respect to the mating part whichserves as a cylinder for the piston.

Detailed description Referring now to FIGURE 1, a valve seat puller 19of this invention is shown positioned with respect to a valve seat 12which is interference fitted within valve body 14 and which is to beremoved therefrom using the puller. The puller is cylindrical in shapeand includes an inner cylindrical portion 16 and outer cylindricalportion 18. The two axially spaced grooves 20 and 22 are adapted .toreceive O-rings 24 and 26 and expansible rings 28 and 39, respectively,the latter of which are positioned exteriorly of the O-rings. The rings28 and 30 are adapted to aid in retaining the O-rings in a sealedposition and prevent any extrusion or leakage during the application ofhydraulic pressure. The axial spacing of the two grooves and O-ringsystems is made such that one is adapted to seal effectively withrespect to the removable seat 12, while the other is adapted to sealwith respect to the valve body 14. A hydraulic pressure channel 32extends between the space between the seal' O-ring system and theexterior of the valve puller 1t} terminating, in

one embodiment, with a valved grease connection 34, which in thisinstance is located along the peripheral edge of the larger diameterbody portion 13. In other instances it may be desirable to remove thethreaded plug 36 and adapt a connection at this point to the channel 32instead of that shown, of course, plugging the other channel opening.

In operation of the embodiment of FIGURE 1, the puller is inserted intothe interior bore of the valve body 14 and valve seat 12 as shown.Suitable hydraulic media such as grease, oil, or others is umped intochannel 32 using an ordinary grease gun, hand pump, or power pumpconnected to element The hydraulic media forces its way through channel32 into the space between the seals and the space between the back edgeof valve seat 12 representing the cross-sectional area of the valveseat. The interference it of valve seat 12 with respect to the valvebody lidserves as a pressure tight seal around the circumference of thevalve seat and hence prevents escape of the hydraulic media. Since inthis embodiment the internal bore within which the uller operates is ofthe same diameter, the forces upon the puller are balanced, permittingincreasing pressure of the hydraulic media without any unbalancingforces on the puller. However, upon sufficient pressure build-upoperating against the effective cross-sectional area of the valve seat12, the valve seat will begin to move axially in its counter bore. Atthis point the product of the annular cross-sectional area of the valveseat and pressure is greater than the frictional interference fitholding force. As the valve seat moves it will also move the pullercausing the seal as to slide with reference to the valve body 14.Continued displacement of the pressure media into the annular Zone willeventually separate the valve seat 12 from the valve body The axialspacing of the two seal systems 24 and 26 is such that the formermaintains its seal with respect to the valve seat 12 and the lattermaintains its seal with respect to the valve body 14 until effectiveseparation is accomplished. Although the hydraulic pressure mediachannel 323 is shown terminating in a connection 34, it is to beunderstood that such connection can be made on the right hand end of thevalve puller, in that instance there is sutlicient room to effectivelyapply hydraulic pressure. however, this would entail disconnecting theline connection with the valve.

The embodiment of FIGURE 2 effectively employs the principles of thisinvention applied, however, to that situation in which the effectiveinternal bore of valve seat 12 with respect to valve body 14 is notequal. Typically, this occurs where the valve body is of the threadedend variety to receive a complementary threaded tubing Accordingly, theapparatus of this embodiment is adapted to provide an inner-cylindricalassembly d2, one end of which is a larger diameter cylindrical portion44. A groove as is adapted to receive O-ring seal 48 and an expansi'bleback-up ring St). A hydraulic pressure media channel 52 extends from theinterior end of the smaller diameter cylindrical portion 42 to anexterior connector 54 for connection to a high pressure hydraulic powersource, not shown. The O-ring 4-3 and back-up ring Eli are adapted tomaintain a sealing engagement with the valve seat 12. Seal adjustmentmember 56 is threadably re ceived axially with respect to cylindricalmembers 42 and 44 being sealed by suitable O-ring 58 with respectthereto. The seal adjustment member 56 extends exteriorly of thecylindrical portion id and includes means for attachment thereto torotate the member, such as by using a ratchet connection, or the like.The other end of the seal adjustment member terminates with aninner-cylindrical body portion on which includes a multiplicity ofelements for maintaining an effective seal between the body portion asand the internal diameter of the tubing 49. A fixed seal is ordinarilynot possible, due to the considerable variance in internal pipediameter. The elements for providing this effective seal include back-upelement 6?.

which retains frictional drag members 64 and 66 which further act asback-up for the resilient seal member es. The frictional drag members 6and as cooperate with respect to an inclined plane 7% by whichadjustable drag with respect to the interior bore of tubing ill iseffected by the rotational movement of the seal adjustment member Member56 is adjusted so as to provide sufiicient frictional drag to offsetthehydraulic unbalance in the puller apparatus.

in operation the preassemblcd apparatus as shown in FEGURE 2 is insertedinternally into the internal bore comprising the valve seat 12 and thetubing 49. An effective seal and frictional drag of elements 68, 61; and54 is produced by rotating the seal adjustment member 56, which in turnrotates body oil with respect to backup member 62 effectively causinggreater or less frictional engagement of members 64 and 66 as itoperates with respect to the inclined plane '70. Once an effective sealis accomplished, hydraulic pressure media, as heretofore described, isforced into that space between seals 48 and 68 to operate against theeffective cross-sectional area of valve seat 12 and thus force relativeseparating movement of the valve seat with respect to the valve body 14-and tubing iii. Once separation has been accomplished, the sealadjustment member is reversely rotated causing a reduction in effectivediameters of elements 64, as and as and hence permitting removal of thesystem from the valve body and pipe line.

The apparatus of FIGURE 3 shows an additional embodiment of thisinvention as adapted for removing a cylindrical bushing 72 from aninterference fit with respect to a die set id, the latter of which isretained to a die holder 7s in sealed relationship using O-ring 78. Inthis instance, as shown, the efiective internal bore of the die holderand the bushing '72 are unequal In that instance a cylindrical puller 8dincludes a sealed groove portion 82 having an O-ring 84 and split ring86 therein as shown which is adapted for sealed engagement with thebushiru 72 and an axially spaced groove 38 adapted to re eive O-ring andsplit Teflon ring 92, which creates an effective hydraulic pressurespace. In that instance the movement length of the bushing '72 withrespect to the die set 74 is greater than the length of the O-ring 9i)will travel upon the respective die holder bore. An auxiliary sealinggroove as having an O-rlng 96 and Teflon split ring 98 therein isprovided for making a secondary effective seal to the die holder and thespace between O-ring 84 for continued hydraulic pressure against bushing72. A hydraulic pressure channel 109 extends from the space between theO-rings to an exterior connection such as zerk run for connection to ahydraulic power source as heretofore described.

In operation the puller 8t) is inserted into the internal bore of thebushing and die holder where effective seal is retainedbetween the two.Thereafter a retainer member fil is attached to the puller body 39 topermit contact of the bushing 72. thereagainst for axial movement ashydraulic pressure is applied.

FIGURE 4 represents an additional embodiment of this invention whereinit is desired to remove a cylindrical bushing Hill as for example from acylindrical shaft 112. In this instance a cylindrical sleeve 114 isadapted with an interiorly directed flange portion 116 which abutsagainst the bushing lit). Spaced grooves 118 and 120 are adapted withsealing assemblies consisting of O-rings 122 and 126, respectively, andsplit rings 124 and 123, respectively. Between the two seals hydraulicpressure fluid conduit 13% terminates with connection 132, forconnection with a hydraulic fluid power source.

In operation hydraulic pressure fluid is forced into that space betweenthe two O-ring seals 122 and 126 and is adapted to operate against theeffective cross-sectional area bushing 11d forcing same outward. Aneffective seal is maintained between the parts by proper axial spacingof the two O-ring systems in order that an effective seal of ring 126with respect to the shaft 112 is maintained until separation of thebushing occurs.

FIGURE 5 describes apparatus for removing bushing 134 from a shaft 136.In that instance the external diameters of the two parts are unequal.Puller 138 is a cylindrical sleeve having an inwardly extending flangeportion 140 for abutting engagement with the bushing 134. Internally ofthe sleeve are two effective diameter groove portions 142 and 144 havingO-ring and Teflon seals 146 and 148, as heretofore described, thereinwhich respectively engage the smaller diameter bushing 134 and thelarger diameter shaft 136 creating a sealed space therebetween having aconnecting conduit 150 and high pressure connection 152. In thisinstance there is a hydraulic unbalance of the uller assembly which isovercome by adding a frictional force to the system. This latter istacomplished by partially cylindrical arcuate wedge block 154 which isadapted to be pressed into tighter frictional engagement with the shaft136 by advancing a cooperating wedge block member 156 toward the rear-Ward end of the puller 138 by threaded adjustment of bolt 158. In thisinstance the net pulling force available to force bushing 134 away fromits shaft 136 is a product of the hydraulic media pressure and the netseal area less the frictional component on the puller as adjusted.

Referring now to FIGURE 6, apparatus is described for removing acylindrical bushing 160 interference fitted with respect to shaft 162,and wherein the external diameter of the bushing is greater than that ofthe shaft. In this instance a pulling sleeve 164 is adapted to fit overthe respective parts and includes a groove 166 having sealing elements168 and groove 170 having sealing elements 172 therein. The formersealing elements are adapted to the peripheral sunface of bushing 160,while the latter abut the peripheral diameter of shaft 162, creating aspace for the injection of hydraulic pressure media through passageway174 and pressure source connection 176. A multiplicity of transverseextension flanges 178 are adapted to be locked to sleeve 164 wherebybushing 160 is adapted to contact the flanges as a part of the overalloperation of the invention.

In operation hydraulic pressure fluid is forced through connection 176and passageway 174 into the space between the sealing elements 168 and172. The net pulling force is sufficient to cause bushing 160 to contactflange elements 178, forcing the sleeve to move axially along the shaftuntil separation of the interference fit is accomplished. The netpulling force is equal to the product of the pressure of the hydraulicmedia pressure and the net seal area exposed to the hydraulic media.

FIGURE 7 shows a two piece puller arrangement for use in a situation aspreviously described with reference to FIGURE 2; that is, where theeffective internal bore of the valve seat 180 is not equal to theeffective internal bore of tubing 182 threadably attached to the body183 of the valve. The tubing sealing structure 184 is substantially thesame as the inner-cylindrical body portion 60 of FIGURE 2 with theexception that seal adjustment member 56 of FIGURE 2 has been removedand replaced by a threaded plug member 186. Plug 186 is provided on itsinner end with a radially extending flange portion 188 that contacts theinner end 190 of tubing 182. Likewise, the inner-cylindrical assembly192 is of the same construction as the inner-cylindrical assembly 42 ofFIG- URE 2 with the exception that seal adjustment member 56 of FIGURE 2is replaced by a pawl actuating arm 194. In operation, the tubingsealing structure 184 is positioned within the end of the tubing andsealing thereof effected in the manner above described. Arm 194 is thenplaced inwardly of cylindrical portion 192 sufficiently to allow thepawls 196 to be manually depressed radially inwardly. Cylindricalportion 192 is then inserted within valve seat 180. Arm 194 is thenpulled outwardly -whereupon the cam surfaces 198 provided near the innerend of the arm urge pawls 196 radially outwardly into engagement withthe inner surfaces 200 of valve seat 180. A pressurized medium is thenforced through channel 202 into the space 204 isolated by the seals 206,208 and 184 to effect the pulling or removal of valve seat 180. Duringthe pulling operation, flange 188 prevents tubing sealing structure 184from being displaced into the tubing. Pawls 196 prevent the cylindricalportion 192 from being displaced from the bore of valve seat 180.

Although there does exist a hydraulic unbalance across this pullingassembly, since the assembly is divided into two parts and means areprovided for preventing displacement of these parts, no frictional dragmechanism is required in thi apparatus.

FIGURE 8 discloses yet another alternate embodiment of this inventionfor the pulling or removal of a valve seat when the effective internalbore of the valve seat is greater than the internal bore of the threadedtubing attached to the valve, similar to the situation reflected inFIGURE 2.

Sleeve 210 having an outwardly extending flange portion 211 is providedon the end opposite flange 211 with annular sealing elements 212 forsealing engagement with the internal bore of valve seat 213. Extendingthrough the central bore 214 of sleeve 210 is a shaft 215, one end ofwhich extend into tubing 216 with the other end remaining inside thebody of the valve. Sealing element 217 sealingly contacts the internalbore of tubing 216. Annular sealing element 218, provided near themiddle portion of shaft 215, provides an annular seal between shaft 215and the internal bore 214 of sleeve 210. Located internally of one endof shaft 215 is a chamber 219 which is in communication with the chamber220 isolated by the sealing elements 212 and 217 of this pullerassembly. Slidably extending into chamber 219 is an elongated piston 222provided with one or more annular sealing rings 224. The external end226 of piston 222 contacts the head of an adjusting screw 228 that is inturn threadably connected to a retainer member 230 that contacts thevalve body at a point opposite the location of the valve seat. Thecross-section of chamber 219 is carefully chosen to equal the dilferencein the sectional areas of the two annular sea-ls .212 and 217.Therefore, any hydraulic unbalance in the puller assembly is transmittedthrough piston 222, screw 228 and retainer member 230 to the valve body.In operation, as hydraulic fluid is pumped into chamber 220 throughpassage 231 the puller assembly and the valve seat will be movedinwardly of the valve body until the valve seat is removed frominterference fit with the body.

Referring now to FIGURE 9, there is shown still another alternateembodiment of thi invention for use in removing a valve seat in asituation such as shown in FIGURE 2. In this embodiment a mechanicalmeans is provided for offsetting the hydraulic unbalance in the pullerassembly. The puller assembly including cylindrical portion 42A, sealadjustment member 56A and the tubing sealing structure composed ofinnercylindrical body portion 60A provided with element 62A, dragmembers 64A and 66A, and seal member 68A are the same as thecorresponding parts shown in FIGURE 2. The head portion of an adjustablescrew 232 contacts the inner end 234 of the seal adjustment member 56A.Screw 232 is threadably received within a retainer member 236 that abutsagainst and is received within the tubular opening in the valve body,opposite the valve seat 12A. Therefore, the hydraulic unbalance of thispulling apparatus is transmitted through screw 232 and retainer member236 to the body of the valve. After hydraulic fluid is pumped intochamber 240 in a manner described in reference to FIGURE 2, screw 232 isbacked otfin small increments to allow movement of the entire pullerassembly and valve seat inwardly of the valve body until the valve seatis removed. Since asavgaea the hydraulic unbalance of this pullerassembly is transmitted to the body of the valve, the frictional dragelements of the assembly may be omitted or may be included simply toassist in effecting a seal against the internal bore of the tubingl-iiA.

Referring now to FIGURE 10, there is shown an alternate embodiment ofthis invention for use in unseating a valve seat in a situation similarto that reflected in FIGURE 2. The tubing sealing structure 238 is thesame as that described with reference to FIGURES 2 and 9. The pullingapparatus of this embodiment is intended to remain stationary while thevalve seat is removed from position in the valve body. Inner-cylindricalportion 24% is substantially elongated axially and is provided withseveral annular sealing elements 242 near one end for sealing engagementwith the internal bore of the valve seat 243. A seal adjustment member246 sealably extends through a central bore 248 in cylindrical member240 and is threadably attached to the tubing sealing structure 238. Thehead portion of an adjuster screw 25% contacts the inner end of sealadjustment member 246 with the threaded portion of screw 256? beingreceived within a frustro-conical shaped retainer member 252. Member 252extends at least part way within the passage 254 through the valve body,opposite the passage including the valve seat 243. Therefore, hydraulicunbalance of this pulling apparatus or assembly is transmitted throughscrew 25%) and retainer member 252 to the body of the valve to preventany lateral movement of the assembly relative to the valve.

When hydraulic fluid is pumped through passage 256 into the chamber 25?isolated by the two parts 238 and 240 of this pulling assembly, thevalve seat 243 will be moved axially along the length ofinner-cylindrical portion 240 and out of seating engagement with thebody of the valve. It should be understood that in order for thisapparatus to be operable there must be a suflicient number of sealingelements 242 spaced over a sufficient length of inner-cylindricalportion 249 to insure a seal between portion 240 and the valve seat 243until the valve seat is completely removed from interference fit withthe valve body.

Referring now to FIGURE 11, there is shown a modifled stationary pullingapparatus for use in pulling or removing valve seat from a valve in asituation as indicated with reference to FIGURE 10. The apparatusdisclosed in FIGURE 11 is intended to remain stationary during thepulling or removing operation with the valve seat moving axially alongthe length of the pulling apparatus. valve seat 260 into contact withthe end 261 of tubing 2.62. Shaft 258 is provided with an annularsealing element 264 for sealing engagement with the end 261 of thetubing 262. Shaft 258 is also provided with a plurality of annularsealing elements 266 that sealably contact the internal bore of valveseat 26%. Adjustable screw 268 and retainer member 27h are provided incontact with one end of shaft 258 for transmitting the hydraulicunbalance in this puller apparatus from the apparatus to the body of thevalve, thereby to hold the apparatus stationary during the pullingoperation. When hydraulic fluid is pumped through passage 272 into thechamber isolated by the sealing elements 266 and 26d of this pullingapparatus, the valve seat 261? will be actuated axially along the lengthof shaft 253 until it is completely unseated from position in the valvebody.

The pulling apparatus as shown in FIGURE 12 is constructed similarly toand operates in the same manner as the pulling apparatus disclosed inFIGURE 11 and discussed above with the exception of the method foreffecting the seal between the shaft 258A and the valve body. As can beseen in the'figure, annular sealing element 273 is of the O-ring typeand is designed to sealably contact the valve bore 27 immediately behindthe valve seat 276.

Inner-cylindrical shaft 258 extends into the it should be noted that theembodiments disclosed in FIGURES 11 and 12 include on the tubing end ofthe puller shaft 253 and 258A, respectively, a plugged hydraulic fluidopening 275% and 289, respectively, which allows operation of thepulling apparatus from the tubing side of the valve.

Referring now to FEGURE 13, there is shown an interference fit valveseat inserter that utilizes the same general theory of operation as thevalve seat pullers above described. The inserter consists of a hydrauliccylinder 23?; having reciprocably disposed therein an elongatedhydraulic piston 28 i. Piston 284 is provided with at least one annularO-ring type sealing element 286 for sealing contact with the bore ofcylinder 282. Valve seat holder 288 is removably received upon theexternal end of piston 234. Holder 28% is provided with a reduceddiameter portion 2% about which the valve seat 292 is positioned.

In operation piston 234 is retracted into cylinder 282. Valve seatholder 288 is then positioned on the external end 289 of piston 284 andvalve seat 292 is slipped about reduced diameter portion 2% of theholder. The thusly assembled apparatus is then positioned Within thevalve body with the valve seat 29 2 positioned adjacent to the openingin the valve body designed to receive it. The closure plate 2% ofcylinder 282 is provided with an annular shoulder 2% t at contacts thevalve body opposite the valve seat. Hydraulic fluid is then introducedinto the cylinder through passage 2%, thereby forcing the piston 284outwardly. Continued outward movement of piston 12% will press valveseat 292 into interference fit with the body of the valve. The hydraulicpressure in the cylinder is then relieved to allow the piston 284 andvalve seat holder 238 to be retracted after which the apparatus isremoved from the valve body.

This invention provides a method of and apparatus for installingpressed-in valve seats and the like and removing same from equipmentinstalled in a place remote from the elaborate and complete facilitiesof a factory. That is, this apparatus permits the use of shrink fitted,press fitted, and interference fitted parts in field repairableequipment.

The apparatus of this invention is easily operable by one man and doesnot require complete disassembly of the valve or similar equipment inwhich it is used.

Also, when removing valve seats and the like from equipment using theapparatus of this invention, there is no galling of the equipment inwhich or upon which the valve seat or similar element is located.

The invention has been described by reference to specific and preferredembodiments. It will be apparent, however, that many modifications canbe made without departing from the spirit and scope of the invention.Accordingly, this invention should be construed not to be limited to theembodiments herein described but should be limited only by the scope ofthe appended claims.

What is claimed is:

l. Apparatus for hydraulically removing a cylindrical shaped elementfrom interference fit with a mating structure comprising:

a substantially cylindrical body portion having a crosssectionalconfiguration to permit said body portion to telescope with respect tosaid element and mating structure;

at least one annular sealing means on said body portion for sealablycontacting the annular surface of said element adjacent to said body;

at least one annular sealing means on said body for sealably contactingsaid mating structure thereby forming an annular hydraulic chamberbetween said sealing means;

passage means through said body to said chamber for the passage ofhydraulic fluid to force said element from lit with said structure;

at least one radially adjustable frictional drag element attached tosaid body portion for frictional engagement with said mating structureto provide a frictional force to offset any hydraulic unbalance in saidapparatus.

said mating structure at a point opposite said element to said firstbody structure to offset any hydraulic unbalance in said apparatus.

4. Apparatus of claim 3 wherein said first body strucshaped element frominterference fit within the bore of a mating structure comprising:

a first substantially cylindrical body portion for limited insertioninto the bore of said mating structure to a 2. Apparatus forhydraulically removing a cylindrical 5 point distant from said elementin a direction opshaped element from interference fit with a matingstrucposite the direction of removal of said element; ture comprising:an annular sealing means on said first body portion for a substantiallycylindrical shaped body portion having a sealably contacting the bore ofsaid mating structure;

cross-sectional configuration to permit said body pora secondsubstantially cylindrical body portion for intion to telescope withrespect to said element and sertion into the bore of said element;mating structure; an annular sealing means on said second body portionat least one annular sealing means on said body porfor sealablycontacting said bore of said element tion for sealably contacting theannular surface of thereby forming a sealed hydraulic chamber betweensaid element adjacent to said body; said first and second body portions;

at least one annular sealing means on said body porat least one retainermeans provided on said second tion for sealably contacting said matingstructure body portion radially movable from a closed position therebyforming annular hydraulic Chamber flush with the annular surface of saidsecond body tween said sealing means; portion to an open position ofcontact with said elepassage means through said body portion to saidchamment on the side opposite the direction of removal of ber for thepassage of hydraulic fluid to force said said element; element from fitWith Said Structure; an operator mandrel extending coaxially throughsaid means extending radially from said body portion for e ond bodyortion movable axially from a first contact with said element as saidelement is forced position to a second position to open said retainerfrom fit with said structure whereby said body is means; moved by and inthe same direction as said element; a passage means through said secondbody portion to a cylindrical Passage extending COaXiauY into one 611dsaid chamber for the passage of hydraulic fluid to of Said y POYtiOll;force said element from fit with said structure.

a lateral, Small diameter, Passage Connecting interior 6. Apparatus forhydraulically removing a cylindrical extremity of Said CylindricalPassage With Said yshaped valve seat from interference fit with a valvebody dl'aulic chamber; comprising in combination therewith:

a Piston fecipfocably received Within Said Cylindrical a cylindricalportion having a cross-sectional configura- P tion to permit saidportion to telescope within said a mechanical linkage contacting at itSone end the Valve seat and valve body one end of termieXtelnal end ofSaid Piston and at its other end with nates outwardly in a largerdiameter portion abuttable said mating structure at a point oppositesaid elei t id valve seat; ment l as Said element is forced fit With afirst annular sealing means on said body portion con- Said matingStructure, Said Piston moves lllwardly tacting against the annularsurface of said valve seat of said cylindrical passage to apply ahydraulic force adjacent to Said bedy;

Sufiicient to Oflset any hydraulic unbalance in Said a second annularsealing means onsaid body contacting apPafatusagainst said valve body toform an annular hydraulic 3. Apparatus for hydraulically removing acylindrical h b b t ee aid sealing means;

shaped element from interference fit with a mating struceach f SaidSealing means Comprising a groove d tum Comprising: spectively outwardfrom said hydraulic chamber a a first substantially cylindrical shapedbody structure resilient Gring and an expansible ring; and

having a cross-sectional configuration to permit said Passage meansthrough Said body to Said chamber for first body structure to telescopewith respect to said the passage of hydraulic fluid to force Said valveSeat element; i from fit with said valve body whereby said valve seat asecond substantially cylindrical shaped body structure contacts saidlarger diameter portion causing Said having a cross-sectionalconfiguration to permit said Valve seat and said apparatus to move inthe Same second body structure to telescope with respect to directionsa1d matmg stmciure; 7. Apparatus for hydraulically removing acylindrical means for cqnnectmg sa1d first and Said Second body shapedinsert from interference fit with a mating structure structures incoaxial end-to-end spaced apart relacomprising: non; a firstsubstantially cylindrical shaped body structure least one annularSealing f sa1d first body having a cross-sectional configuration topermit said struciuw for sealtbly contacimg t annular Surface first bodystructure to telescope with respect to said of sa1d element ad acent tosa1d body, insert;

at least one annular seahng mealis on t secfmd body a secondsubstantially cylindrical shaped body structure structure for sealablycontacting sa1d mating struch l nfi t ture thereby forming an annularhydraulic chamber avmg a Cross sec Iona co gum Ion Penm Sal b o0 secondbody structure to telescope with respect to etween sa1d sealmg means,sa1d mating structure,

passage means through said body to sa1d chamber for f fir t d d b d thepassage of hydraulic fluid to force said element means or cc-mnec Sal San Sal scon y fmm fit With Said structure structures in coaxialend-to-end spaced apart relation;

a variable length mechaniczil linka e extending from at least oneannular Sealing means on sa1d first body b 5 structure for sealablycontacting the annular surface of said insert adjacent to said body;

at least one annular sealing means on said second body structure forsealably contacting said mating structure thereby forming an annularhydraulic chamber ture is provided with at least one radial extensionfor contact with said element as said element is forced from fit withsaid mating structure and said linkage is progressively shortened toallow said body and said element to move relative to said matingstructure.

5. Apparatus for hydraulically removing a cylindrical between saidsealing means;

passage means through said body to said chamber for the passage ofhydraulic fluid to force said insert from fit with said structure; and

means for opposing and offsetting any hydraulic unbalance in saidapparatus including at least one radially asst pee it adjustablefrictionable drag insert attached to said second body structure forfrictional engagement with said mating structure.

8. Apparatus for hydraulically removing a cylindrical shaped insert frominterference fit With a mating structure comprising: 7

a first substantially cylindrical shaped body structure having across-sectional configuration to permit said first body structure totelescope With respect to said insert;

a second substantially cylindrical shaped body structure having across-sectional configuration to permit said second body structure totelescope With respect to said mating structure;

means for connecting said first and said second body structures incoaxial end-to-end spaced apart relation;

at least one annular sealing means on said first body structure forsealably contacting the annular surface of said insert adjacent to saidbody;

at least one radially adjustable annularsealing means on said secondbody structure for sealably contacting said mating structure therebyforming an annular hydraulic chamber between said sealing means;

passage means through said body to said chamber for the passage ofhydraulic fluid to force said insert from fit with said structure; and

means included in said apparatus for opposing and oilsetting anyhydraulic unbalance in said apparatus.

References (fited by the Examiner UNITED FOREEGN PATENTS Germany.

W ELLIAM FELDMAN, Primary Examiner.

J. C. PETERS, Assistant Examiner.

6. APPARATUS FOR HYDRAULICALLY REMOVING A CYLINDRICAL SHAPED VALVE SEATFROM INTERFERENCE FIT WITH A VALVE BODY COMPRISING IN COMBINATIONTHEREWITH: A CYLINDRICAL PORTION HAVING A CROSS-SECTIONAL CONFIGURATIONTO PERMIT SAID PORTION TO TELESCOPE WITHIN SAID VALVE SEAT AND VALVEBODY, ONE END OF WHICH TERMINATES OUTWARDLY IN A LARGER DIAMETER PORTIONABUTTABLE AGAINST SAID VALVE SEAT; A FIRST ANNULAR SEALING MEANS ON SAIDBODY PORTION CONTACTING AGAINST THE ANNULAR SURFACE OF SAID VALVE SEATADJACENT TO SAID BODY; A SECOND ANNULAR SEALING MEANS ON SAID BODYCONTACTING AGAINST SAID VALVE BODY TO FORM AN ANNULAR HYDRAULIC CHAMBERBETWEEN SAID SEALING MEANS;